Lubricating oil composition

ABSTRACT

The incorporation of at least one of certain nitrogen-oxygen containing compounds into lubricating oil compositions comprising mineral oil of lubricating viscosity and at least one alkali metal and/or alkaline earth metal carbonate overbased sulfonate and/or phenate improves the wear properties of the lubricating composition toward metals, in particular silver. These lubricating oil compositions may be used by maintaining a lubricating amount of the composition on the components of an internal combustion engine, in particular a railroad diesel engine having silver components, requiring lubrication.

United States Patent [191 Devries Dec. 18, 1973 1 1 LUBRICATING OILCOMPOSITION Donald L. Devries, South Holland, 111.

[22] Filed: Feb. 5, 1971 [21] Appl. No.: 113,041

[75] Inventor:

[52] U.S. Cl. 252/334, 252/427, 252/51.5 R, 252/392 [51] Int. CI. Cl0ml/32',C10m 1/40 [58] Field of Search 252/515 R, 392, 252/33, 33.4, 42.7

[56] References Cited UNITED STATES PATENTS 2,629,693 2/1953 Barton eta1. 252/334 2,865,956 12/1958 Ellis et alum. 252/33 X 2,956,018 10/1960Carlyle et a1. 252/325 X 3,036,971 5/1962 Otto l 252/427 2,268,6081/1942 McNulty et 252/515 R 2,298,640 10/1942 Prutton 252/515 R3,337,472 8/1967 Littler et a1 l 252/392 3,412,029 11/1968 Andress eta1, 252/515 R 3,018,291 1/1962 Anderson et a1. 252/515 A 3,256,1896/1966 Petersen et al7 252/498 X FOREIGN PATENTS OR APPLICATIONS1,180,389 2/1970 Great Britain 252/515 R 551,067 12/1957 Canada 252/515R Primary ExaminerDaniel E. Wyman Assistant ExaminerW. J. ShineAttorneyThomas .1, Clough, Frank J. Uxa and Blutcher S. Tharp [57]ABSTRACT The incorporation of at least one of certain nitrogen- 77 7oxygen containing compounds into lubricating oil compositions comprisingmineral oil of lubricating viscosity and at least one alkali metaland/or alkaline earth metal carbonate overbased sulfonate and/or phenateimproves the wear properties of the lubricating composition towardmetals, in particular silver. These lubricating oil compositions may beused by maintaining a lubricating amount of the composition on thecomponents of an internal combustion engine, in particular a railroaddiesel engine having silver components, requiring lubrication.

32 Claims, N0 Drawings LUBRICATING OIL COMPOSITION This inventionrelates to new and improved lubricating compositions. More particularly,it relates to mineral oil lubricating compositions which have improvedwear properties toward metals such as, for example, silver, alloys ofsilver and the like.

Mineral oil lubricating compositions which are used in severe service,for example, as lubricants for railroad diesel engines areadvantageously alkaline in nature. The alkalinity is desired toneutralize certain acids which are formed in the engine duringoperation. The alkalinity can be supplied to these lubricatingcompositions from various sources. Typical among these sources are, forexample, normal alkali metal and alkaline earth metal phenates.

Other possible sources of alkalinity for these lubricating compositionsare the alkali metal and alkaline earth metal carbonate overbasedsulfonates and phenates. However, the incorporation of these overbasedcomponents into the lubricating compositions, while being an efficientand economical source of alkalinity, can cause unacceptable wear tocertain engine components; for example, silver wrist pin bushingsinrailroad diesel engines and the silver bearing surfaces in aircraftengines. It, therefore, would be advantageous to use these overbasedmaterials to provide at least a portion of the desired alkalinity tolubricating oil compositions without causing undue wear tometal'components, and in particular to silver components;

Therefore, one of the objects of the present invention is to provide alubricating oil composition which includes alkali metal and/or alkalineearth metal carbonate overbased sulfonates and/or phenates and whichhave improved wear properties toward metals, in particular silver andsilver alloys. Other objects and advantages of the present inventionwill become apparent hereinafter.

it has now been discovered that the incorporation of at least one ofcertain nitrogen-oxygen containing compounds into lubricating oilcompositions containing at least one alkali metal and/or alkaline earthmetal carbonate overbased sulfonate and/or phenatc improves the wearproperties of the lubricating composition toward silver. ln one aspect,the present invention is a lubricating oil composition which comprises amajor proportion of oil of lubricating viscosity; at least one carbonateoverbased salt present in an amount sufficient to contribute alkalinityto the lubricating composition, said carbonate over-based salt beingselected from the group consisting of alkali metal sulfonate,alkalineearth metal sulfonate, alkali metal phenate, alkaline earthmetal phenate, and mixtures thereof, and overbased as the correspondingcarbonate; and at least one oil-miscible compound selected from thegroup consisting of and mixtures ofl and II, wherein the total number ofcarbon atoms contained in l is between one and about 100, preferablybetween about two and about 30, and the total number of carbon atomscontained in II is between eight and about 100, preferably between abouteight and about 35; a is an integer from 1 to 3 and b is from zero to 1,provided that the number of valance bonds to N always totals 3; Rcontains from one to about four carbon atoms and is selected from thegroup consisting of a di-valent hydrocarbon radical and a substituteddi-valent hydrocarbon radical; R and R each have from zero to aboutcarbon atoms and are independently selected from the group consisting ofH, R-OH, a monoand di-valent hydrocarbon radical, a substituted monoandsubstituted di-valent hydrocarbon radical, said di-valent andsubstituted di-valent radical having both valance bonds on the carbonatom which is attached to N; and when a and b are both 1, R and R incombination with N can form a ring structure having at least one cyclicportion,said ring structure being selected from the group consisting ofa heterocyclic ring and a substituted heterocyclic ring, said cyclicportion comprising from four to six total atoms, from three to fivecarbon atoms and from one to three hetero-atoms, said hetero-atoms inaddition to N being independently selected from the group consisting ofN, O and S, said substituents of the substituted heterocyclic ring beingindependently selected from the group consisting of a monovalenthydrocarbon radical, a nonhydrocarbon substituted mono-valenthydrocarbon radical, OH and NH said total ring structure comprising fromthree to about 100, preferably from about four to about 30, carbonatoms; and when a is l, R and R in combination with N can form a ringstructure having at least one cyclic portion including N, said ringstructure selected from the group consisting of a heterocyclic ring, asubstituted heterocyclic ring, a condensed aromatic heterocyclic ringand a substituted condensed aromatic heterocyclic ring, said cyclicportion comprising from four to six total atoms, from three to fivecarbon atoms and from one to three heter-atoms, said hetero-atoms inaddition to N being independently selected from the group consisting ofN, O and S, said substituents of the substituted heterocyclic ring andsubstituted condensed aromatic heterocyclic ring being selected from thegroup consisting of a mono-valent hydrocarbon radical, a non-hydrocarbonsubstituted mono-valent hydrocarbon radical, OH and NH said total ringstructure comprising from three to about 100, preferably from about fiveto about 25, carbon atoms; R has from zero to about 30 carbon atoms andis selected from the group consisting of H, a mono-valent hydrocarbonradical, a substituted mono-valent hydrocarbon radical, and

....N=clj wherein R and R each individually have from zero to about 30carbon atoms and are independently selected from the group consisting ofH, a mono-valent hydrocarbon radical and a substituted mono-valenthydrocarbon radical said oil-miscible compound being present in anamount sufficient to improve the wear properties of the lubricatingcomposition toward metal, in particular silver. In each of the abovestructural formulas it is preferred that the N and OH be separated byfrom one to four, more preferably two to three, carbon atoms.

When a and b are both 1, and R, and R are not combined with N into aring structure, it is preferred that R, and R be independently selectedfrom the group consisting of H and R-OH where R is an alkyl radicalhaving from one to four, more preferably two to three carbon atoms.Thus, the nitrogen-oxygen containing wear modifiers include the loweralkanol-amines. When either R and R, or R, and R are combined with N toform a ring structure, it is preferred that the cyclic portion of saidring structure containing N comprise from five to six total atoms andthat all hetero-atoms be N. When the wear modifier is defined bystructure (ll) above, it is preferred that R be and that R be selectedfrom the group consisting of H and alkyl radical, said alkyl radicalhaving between 1 and about 18 carbon atoms.

Typical examples of di-valent hydrocarbon radicals represented by Rwhich are suitable include alkylene such as ethylene, propylene,butylene and the like radicals; alkylidene such as ethylidene,propylidene, butylidene and the like radicals; alkenylene such aspropenylene, butenylene and pentenylene and the like radicals;alkenylidene such as propenylidene, butenylidene, pentenylidene and thelike radicals; arylene such as phenylene, naphthylene and the likeradicals; aralkylene such as phenyl ethylene and the like radicals;aralkylidene such as phenylpropylidene and the like radicals; alkarylenesuch as ethyl phenylene and the like radicals. In choosing thehydrocarbon radicals to be used, the proviso that the number of valancebonds to N always total 3 must be adhered to. For example, if b is zeroand R and R, are not combined with N into a ring structure, then eitherR or R, must be alkylidene, alkenylidene or their substituted analogs.Similarily, ifa and b are 1 and R, and/or R is a hydrocarbon radical,these radicals cannot be di-valent.

Typical examples of the mono-valent hydrocarbon radicals represented byR,, R R,,, R and R which are suitable include alkyl such as methyl,ethyl, propyl, lauryl, stearyl and the like radicals; alkenyl such asethylenyl, propenyl, butenyl, oleyl, linoleyl and the like radicals;aryl such as phenyl, naphthyl and the like radicals; alkaryl such asmethyl phenyl, ethyl phenyl, propyl phenyl and the like radicals;aralkyl such as phenyl methyl, phenyl ethyl, phenyl propyl and the likeradicals. In each instance in which a substituted radical is called for,it is contemplated to include all those substituents which do notmaterially interfer with the wear improving properties of the compound.lncluded among these non-interfering substituents are OH, NH CL, SH andthe like radicals.

Compounds which are particularly preferred for improving the wearproperties of the lubricating composi-' tions of the present inventiontoward silver are those selected from the group consisting of 8-hydroxyquinoline; disalicylal propylene diimine; lhydroxyethyl,2-alkeny] imidazoline; l-hydroxy'ethyl, 2-alkyl imidazoline and mixturesthereof, wherein the alkenylrand alkyl groups contain between aboutseven and about 29 carbon atoms. Y

The nitrogen-oxygen containing compounds def ned above'are present inthe lubricating oil compositions in an amount sufficient to improve thewear properties of the lubricating oil compositions toward metal, inparticular toward silver. It is preferred to utilize concentrations ofat least about 0.01 percent by weight'of these nitrogen-oxygencontaining compounds in the lubricating oil compositions. In order toobtain the maximum benefits from the present invention, it is morepreferred to use at least about 0.05 percent by weight and still morepreferably at least about 0.1 percent by weight of these compounds. Foreconomic reasons, it is preferred to limit the concentration of thesecompounds to about 2.0 percent by weight of the total lubricatingcomposition. Therefore, these nitrogen-oxygen containing compoundsshould preferably comprise from about 0.01 percent to about 2.0 percent,more preferably from about 0.05 percent to about 2.0 percent andoptimally from about 0.1 percent to about 2.0 percent, by weight of thetotal composition. It is, of course, understood that more than oneeffective nitrogen-oxygen containing compound may be used in combinationin a single lubricating composition and such a composition is within thescope of the present invention. The proportions given above apply to thetotal amounts of these compounds regardless of how many are used.

The oils used in the compositions of the present invention are thoseconventionally used in lubricant manufacture. The suitable lubricatingoils include those having a viscosity within the range of about 50 SUSto about 2000 SUS at 100F. These oils may be refined or otherwiseprocessed to produce an oil having the desired quality. Although mineraloils are preferred, the oil may be synthetic in nature. Typical of theoils used in the present invention is a mineral oil having a viscosityof about 1000 SUS at 100F. Combinations of two or more different oils ina single lubricating composition are within the scope of the presentinvention. The lubricating oil comprises a major proportion, preferablyat least about percent, still more preferably at least about by weight,of the total composition.

The carbonate overbased sulfonates and phenates contribute at least aportion of the alkalinity to the lubricating compositions of the presentinvention. Although the degree of alkalinity of these compositions mayvary widely and is, therefore, not critical, it is preferred that thelubricating oil compositions of the pres- .ent invention have a positiveTotal Base Number (TBN) of less than about 15, more preferably less thanabout 10. The term Total Base Number or TBN as used herein refers to ameasure of alkalinity. The TBN is determined through the use of testprocedure ASTM D-664 which involves titrating a sample containing thelubricating oil composition being tested to a pH of 4. The overbasedsalts are normally present in the lubricating oil compositions of thepresent invention in a minor amount, preferably in an amount from about0.1 percent to about 8 percent and more preferably from about 0.25percent to about 5 percent, by weight of the total composition. Theseoverbased materials can be added to the lubricating oil as a dispersionin oil or other fluid. The above-noted proportion range is based on theactive overbased sulfonate and phenate. More than one overbased salt maybe used in the lubricating compositions of the present invention. Theproportions given above apply to the total amount of these saltsregardless of how many are used.

The alkali metal (i.e., sodium, potassium and lithium) and alkalineearth metal (i.e., magnesium, strontium, barium and calcium) carbonateoverbased alkali metal and alkaline earth metal sulfonates which may beincorporated into the compositions of the present invention comprise:(l) alkali and alkaline earth metal salts of sulfonic acids; and (2)dispersed solid particles of alkali metal and alkaline earth metalcarbonates.

sulfonates derived from sulfonic acids having about 12 to about 200carbon atoms per molecule are of particular usefulness in the presentinvention. Among the sulfonic acids are the following: mahogany sulfonicacids, petrolatum sulfonic acids, mono-and polywax substitutednaphthalene sulfonic acids, phenol sulfonic acids, diphenyl ethersulfonic acids, diphenyl ether disulfonic acids, naphthalenedisulfide-sulfonic acids, naphthalene disulfide disulfonic acids,diphenyl amine disulfonic acids, cetyl-phenol mono-sulfide sulfonicacids, cetoxy capryl-benzene sulfonic acids, di-cetyl thianthrenesulfonic acids, such as cethyl chlorobenzene sulfonic acids,cetyl-phenol sulfonic acids, cetylphenol disulfide sulfonic acids,cetyl-phenol monosulfide sulfonic acids, cetoxy capryl-benzene sulfonicacids, di-cetyl thiathrene sulfonic acids, di-lauryl betanaphthaolsulfonic acids and di-capryl nitronaphthalene sulfonic acids, aliphaticsulfonic acids such as paraffin wax sulfonic acids, unsaturated paraffinwax sulfonic acids, hydroxy substituted paraffin wax sulfonic acids,tetraisobutylene sulfonic acids, tetra-amylene sulfonic acids,chloro-substituted paraffin wax sulfonic acids, nitroso paraffin waxsulfonic acids, etc., cycloalip'hatic sulfonic acids, such as petroleumnaphthene sulfonic acids, cetyl-cyclopentyl sulfonic acids,laurylcyclohexyl sulfonic acids, bis-(diisobutyl)-cyclohexyl sulfonicacids, monoand poly-wax substituted cyclohexyl sulfonic acids, etc.

With respect to the sulfonic acids, it is intended herein to employ theterm petroleum sulfonic acids" to cover all sulfonic acids which arederived at least in part from petroleum products. Additional examples ofsulfonic acids and/or the alkali and alkaline earth metal salts thereofwhich can be employed as starting materials are disclosed in thefollowing U. S. Pat. Nos.:

2,174,110; 2,174,560; 2,174,508; 2,193,824; 2,197,800; 2,020,791;2,212,786; 2,213,360; 2,228,598; 2,233,676; 2,239,974; 2,263,312;2,276,090; 2,276,097; 2,315,514; 2,319,121; 2,321,022; 2,333,568;2,333,788; 2,335,259; 2,337,552; 2,346,568; 2,366,027; 2,374,193 and2,383,319.

The more preferred class of carbonate overbased sulfonates are thecalcium sulfonates overbased with calcium carbonate. Calcium sulfonatesoverbased with calcium carbonate can be obtained by passing carbondioxide through a mixture of neutral calcium sulfonates, mineral oil,lime and water. The formation of the overbased sulfonates can be aidedthrough the use of promoters," such as phenols, aromatic amines, sucroseand lower aliphatic alcohols. Many patents have been issued whichdisclose processes for making calcium carbonate overbased sulfonates.Among these are U.S. Pat. Nos. 2,865,956 and 2,956,018. The otheroverbased sulfonates useful in the present invention can be prepared bymethods analogous to that given above for the overbased calciumsulfonates.

The alkali metal and alkaline earth metal carbonate overbased alkalimetal and alkaline earth metal phenates which may be incorporated intothe compositions of the present invention comprise: (l) alkali andalkaline earth metal phenates; and (2) dispersed solid particles ofalkali metal and alkaline earth metal carbonates. The preferredoverbased phenates for use in the present invention are the calciumphenates overbased with calcium carbonate. The phenates may bepolymerized, for example, by reaction with elemental sulphur to formsulphurized phenates. The sulphurized phenates,

wherein A is an essentially hydrocarbon" aromatic radical, preferably abenzene radical, R is a cyclic, straight-chained or branched-changed,saturated, essentially hydrocarbon radical having from four to 30 carbonatoms, 0 represents oxygen, 0 is a number having a value of l to 5.

By essentially hydrocarbon (i.e., hydrocarbonaceous) radical is meantthose radicals which are composed mainly of hydrogen and carbon, andinclude such radicals which contain, in addition, minor amounts ofsubstituents, such as chlorine, bromine, oxygen, sulfur, nitrogen andthe like, which do not substantially affect their hydrocarbon character.Examples of suitable hydrocarbonaceous radicals include alkyl radicalssuch as butyl, hexyl, octyl, decyl, dodecyl, hexadecyl, eicoxyl,triacontyl radicals; radicals derived from petroleum hydrocarbons, suchas white oil, wax, olefin polymers (e.g., polypropylene andpolybutylene), etc.; aryl radicals such as phenyl, naphthyl, etc.;aralkyl radicals such as phenyloctyl, phenyldecyl, phenyloctadecyl,etc.; alkaryl radicals such as amylphenyl, cetylphenyl, etc.; and cyclicnon-benzenoid radicals, such as cyclohexyl, bornyl, etc.

Examples of calcium phenates include the calcium salts of octyl phenol,decyl phenol, dodecyl phenol, tetradecyl phenol, hexadecyl phenol,triacontyl phenol and the like.

Both the unsulphurized and the sulphurized phenates can be overbasedwith carbonate by treating the phenate with carbon dioxide such asdisclosed in U.S. Pat. No. 3,036,971.

It is preferred that the lubricating compositions of the presentinvention include at least one detergent. Both the ash-containingdetergents, such as the conventional metal based detergents, and theashless detergents are suitable for use. However, it is preferred to usethe ashless detergent in the compositions of the present invention.Although the detergents are not effective by themselves tosatisfactorily reduce the wear characteristics of the lubricatingcompositions toward silver, they may enhance the silver anti-wearproperties of the compositions containing the nitrogen-oxygen containingcompounds of the present invention. When these detergents are includedin the compositions of this invention, they comprise from about 1percent to about 6 percent by weight of the total composition.

In general, the ashless detergents suitable for use are compounds whichcomprise an oil solubilizing tail and polar detergent head. Many ashlessdetergents fitting this general description are known to the art and arecommercially available. For example, basic polyamines substituted withlong chain hydro-carbons having from about 30 to about 200 carbon atomsto provide oleophilic character are suitable for use in the presentinvention. Specific examples of this type of ashless detergent are theN-dialkylaminoalkyl alkenyl succinimides, wherein the alkenyl groupcontainsfrom about 30 to about 200 carbon atoms, and the divalentalkylene radical along with the two alkyl radicals contain a total ofless than about 10 carbon atoms. See U.S. Pat. No. 3,018,291, which ishereby incorporated by reference into the present application. Therequired polarity may be supplied by groups containing, for example,oxygen, halogen, sulfur, phosphorous as well as nitrogen and mixturesthereof. For example, an ashless detergent can be derived by reactinghydrocarbon polymer containing from about 30 to about 200 carbon atomswith P 5 See U.S. Pat. No. 3,003,964; and British Pat. No. 815,810; alsoU.S. Pat. Nos. 3,256,189 and 3,256,194, which patents are herebyincorporated by reference into the present application. All of thesesuitable ashless detergents may be generally characterized as compoundscomprising a hydrocarbon portion of sufficient size to render thecompound oil soluble and at least one non-metallic polar portion whichprovides a substantial part of the detergent action.

In addition to the additives already described, lubricating oilcompositions contemplated herein may contain other agents, such as pourpoint depressants, oiliness agents, blooming agents, compounds forenhancing the viscosity index of the lubricating oil, peptizing agents,etc.

The lubricating oil compositions of the present invention can be used tolubricate internal combustion engines, and in particular, engines havingsilver components, such as, for example, many railroad diesel engines.More specifically, the lubricating oil compositions of the presentinvention can be used to reduce the wear of metal, in particular silver,engine components which normally occurs during the operation of theengine. Maintaining (or causing to be maintained) a lubricating amountof the oil compositions of the present invention on internal combustionengine components such as bearing surfaces, wrist pin bushings and thelike, requiring lubrication and/or wear improvement results in obtainingsubstantial benefits from the present invention.

The lubricating oil compositions of the present invention were testedfollowing the two procedures given below. The first procedure is alaboratory test which has been developed to study silver lubrication.This test is described in detail in a paper given at the NationalCombined Fuels and Lubricants and Transportation Meetings in Houston,Texas, on November 4, thru 7, 1969. The title of the paper is A BenchTest for the Evaluation of Silver-Steel Lubrication Properties ofRailroad Diesel Oil, by B. W. Turnquest, P.G. Culliney, R. .l. Danehy,and R. D. Pullman. Results from this bench test procedure correlatequite well with actual engine test results and, therefore, provide areasonable indication of the true utility of the lubricating oilcomposition being tested.

This procedure utilizes the Sinclair Pin and Disc Machine. Basically,this apparatus is of the pin-on-disc type, in which a loaded rider rubsagainst the flat surface of a rotating disc. Contact of the rideragainst the disc is effected by means of a lever and cam arrangementwhich permits split-second initiation and termination of rubbing. Thesilver pins which are to be tested are attached to the rider and haveconical ends. The in-' cluded angle of the cone is 120 deg. so that themeasured increase in the diameter of the work wear scar is 3.46 timesthe axial depth of wear. In a wear experiment the primary observation isthe increase'in the diameter of the truncated area of the cone. Providedthe perimeter of the scar is clearly elineated, wear measurementssensitive to 2 X 10 inches as scar diameter (or 3 X 10 inches as wearscar depth) are feasible.

Using this apparatus and measuring procedure, the lubricants of thepresent invention are tested as follows. The lubricant is supplied tothe rubbing zone by allowing it to flow onto the disc from a reservoir.The supply tube is positioned so that the lubricant stream impinges uponthe leading edge of the rider with reference to the motion of the disc.Band heaters are fitted to the lubricant reservoir and the receivingbath for experiments carried out at elevated temperatures. Alternately,the disc may be submerged in the test oil. The conically ended silverpins were used on mirror finished steel discs. The same break-inprocedure is followed in all cases. In the first stage of the break-inprocedure, the silver pins are run on ground steel discs until rubbingsurfaces of appropriate size are established. A gram load is applied inall cases during the first stage of the break-in procedure and white oilis used as the lubricant. In the final stage of the break-in, the pinsare run for approximately 15 minutes in the test lubricant and on themirror finished surface of the disc. A 800 gram load is applied in thefinal break-in stage.

The actual test is run at the following conditions: pressure of 7,500psi., rubbing speed of 20 feet per minute (fpm) and a constanttemperature of 200F. The test is continued for a sufficient length oftime to allow an accurate measurement of the increase in the diameter ofthe truncated area of the pin. Depending on the wear rate observed, theoperating time per experiment can vary from about 280 to about 500minutes. Bench test wear rates of less than about 10 X 10 inches perfoot rubbed indicate that the lubricant being tested has satisfactoryanti-wear properties.

The second testing procedure involves using the various lubricants in anEMD 2567 test engine. This engine utilizes a D-l type power assembly.Each new test involves using various new components. Among these newcomponents are the silver piston pins and special unleaded pin insertbearings. These components are installed at the beginning of each test.Each engine test includes 9 hours and 20 minutes of pre-run and 25 hourson test. Below is a table of typical conditions for the engine test.

TYPICAL 25 HOUR OPERATING CONDITIONS Engine type EMD 2567 Cylinders, No.2 Bore, in. 8.50

Stroke, in. 10.0

Compression ratio 20.1

Test Duration, Hr. 25

Engine load, BHP 208.8

Engine speed, rpm. 835

Fuel sulfur content, Wt. percent 1.0

Oil Temp. to bearings, F. 238

Oil Temp. to engine, F. 210

Coolant temp. (out), F. 184

Engine Oil Pressure, psi. 55

inlet air temp., F. 95

Airbox temp., F. 160

Air box pressure, in. Hg. 6.8

Exhaust temp., F. 905

Exhaust pressure, in. Hg. 0.5

EMD Engine bearing ratings of the anti-wear properties of thelubricating oil are done on a numerical basis as prescribed by EMD withthe following relationship. EMD Silver Bearing Rating System Excellentoil 20 40 Good Oil 40 75 Borderline Oil 75 Failure The followingexamples illustrate more clearly the compositions of the presentinvention. However, these illustrations are not to be interpreted asspecific limita tions on this invention.

EXAMPLE 1 A lubricating oil composition was prepared by blendingtogether a mineral oil of lubricating viscosity (about 900 SUS at 100F.)with a calcium carbonate overbased calcium sulfonate-oil mixture havinga TBN of about 280. The sulfonate was derived from petroleum sources andcontained about carbon atoms per molecule. Lubricating oil compositionshaving a total base number of 3 (containing 1.05 percent by weight ofthe overbased sulfonate mixture) and 6 (containing 2.1 percent by weightof the overbased sulfonate mixture) were prepared.

Each lubricating oil composition was evaluated according to the benchprocedure described previously. The table below gives the average wearrate based on a series of three tests with each composition.

Bench Test Wear Rate at 7500 psi. and 20 fpm.,

Total Base Number in./ft. X 10" EXAMPLE 2 The lubricating oilcomposition of Example 1 having a total base number of 6 was furthermodified to include about 3 percent by weight of an ashless detergent.The detergent comprises as an oil solubilizing portion, a hydrocarbonolefin polymer containing an average of about 75 carbon atoms and toprovide a substantial part of the detergency action, a polar portioncontaining basic nitrogen. This commercially available detergentcontains 1.2 percent nitrogen and has a total base number of about toabout 40. The bench test procedure resulted in a wear rate of 16 X 10'in./ft. using the composition including this ashless detergent. Thisresult when compared to Example 1 indicates that the ashless detergentdoes act to improve somewhat the wear properties of the lubricatingcomposition toward silver.

EXAMPLE 3 to 14 Lubricating oil compositions were prepared according tothe manner of Example 1 with alkalinity being supplied by the samecalcium carbonate overbased calcium sulfonate-oil mixture. Each of thecompositions included nitrogen-oxygen containing wear modifiers. Eachcomposition was tested by means of the bench test procedure and theresulting wear rates are reported below.

Bench test wear rate, in./1t. 10-

Total base No.

Wear modifier and concentration,

Example wt. percent ...do 1.0% triethanolamine 0.5% diisopropanolamlne 10.5% 8-hydroxyquinollne 0.1% S-hydroxyquinoline, 0.5% l-hydroxyethyl,Z-heptadecenyl imidazoline. 1.0% l-hydroxyethyl, 2-heptadecenylimidazoline. 0.6% disalieylal propylene diimine. 0.3% 1,3,5-tris(Zhydroxyethyl) s-triazine. 0.3% salieylideneaminoquanidine ta L9. 0.3%3-hydroxypyridine 0.3% Z-hydroxypyridine 0.4% o-aminophenol Each of thenitrogen-oxygen containing compounds used as wear modifiers can becharacterized fitting one ofthe structural formulas given previously.The results of these tests demonstrate that all these compoundssubstantially improve the wear properties of lubricating oilcompositions containing carbonate overbased salts toward silver.

EXAMPLE 15 EXAMPLE 16 and 17 Two lubricating oil compositions wereprepared according to the procedure of Example 15 except that onecomposition included 1.0 percent by weight of triethanolamine and theother composition included 0.4 percent by weight monoethanolamine. Theaddition of these additives gave the following bench test results:

Nitrogen-Oxygen Containing Bench Test Wear Example TBN Additive Rate,in./ft.X 10 15 6 None 16 6 1.0% Triethanolamine 10.8 17 6 0.4%Monoethanolaminc 1.6

EXAMPLE 18 to 22 Lubricating oil compositions were prepared according tothe manner in Example 1. Each composition, with the exception of thatused in Example 18, include 3 percent by weight of the ashless detergentdescribed in Example 2. Each of the compositions were tested using theEMD Engine Test described previously. Results of these tests arepresented below.

A lubricating oil composition containing no ashless detergent and wearmodifier when engine tested results in severely damaged (i.e., wipedout) bearings. Examples l8 and 19 indicate that the use of an ashlessdetergent may enhance the silver wear properties of the composition.

Aside from the bearing wear measurements noted above, the oilcompositions in Examples 18 to 22 were effective lubricating oils and,therefore, were acceptable lubricants.

The preceding examples demonstrate the outstand ing effectiveness of thenitrogen-oxygen containing wear modifiers defined herein. Not only havelubricating oil compositions which include these wear modifiers beenshown to be effective diesel engine lubricants, but also theselubricating compositions have outstanding wear properties when appliedto metal, in particular silver, engine components.

Examples 1, 2 and 15, when analyzed in view of the other examples,demonstrate that the oil compositions which do not include thenitrogen-oxygen containing wear modifiers have substantially poorer wearproperties toward silver than do the compositions of the presentinvention. Although oil compositions which include ashless detergentsshow an improvement in silver wear over oils not containing the ashlessdetergents, a still more enhanced silver wear improvement is obtainedusing the ashless detergent in combination with the nitrogen-oxygencontaining additives defined herein.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A lubricating oil composition comprising a major proportion of an oilof lubricating viscosity; at least one carbonate overbased salt presentin an amount sufficient to contribute alkalinity to said lubricating oilcomposition, said carbonate overbased salt being selected from the groupconsisting of alkali metal sulfonate, alkaline earth metal sulfonate,alkali metal phenate, alkaline earth metal phenate and mixtures thereofand overbased as the corresponding carbonate and mixtures thereof; andat least one oil-miscible compound selected from the group consisting ofN-R-O H ah,

and

( disaly lglpropylenediimine and mixtures OH and II, wherein the totalnumber of carbon atoms contained in I is between 1 and about a is aninteger from 1 to 3 and b is from zero to 1, provided that the number ofvalance bonds to N always totals 3; R contains from one to about fourcarbon atoms and is selected from the group consisting of a divalenthydrocarbon radical and a substituted di-valent hydrocarbon radical; Rand R each have from zero to about 100 carbon atoms and independentlyselected from the group consisting of H, R-OH, a monoand divalenthydrocarbon radical, a substituted mono-and substituted di-valenthydrocarbon radical, said divalent and substituted di-valent radicalhaving both valance bonds on the carbon atoms which is attached to N;and when a and b are both 1, R, and R in combination with N can form aring structure having at least one cyclic portion, said ring structurebeing selected from the group consisting of a heterocyclic ring and asubstituted heterocyclic ring, said cyclic portion comprising from fourto six total atoms, from three to five carbon atoms and from one tothree hetero-atoms, said heteroatoms in addition to N beingindependently selected from the group consisting of N, O and S, saidsubstituents of the substituted heterocyclic ring being independentlyselected from the group consisting of a monovalent hydrocarbon radical,a non-hydrocarbon substituted mono-valent hydrocarbon radical, OH and NHsaid total ring structure comprising from three to about 100 carbonatoms; and when a is l, R and R in combination with N can form a ringstructure selected from the group consisting of a heterocyclic ring, asubstituted heterocyclic ring, a condensed aromatic heterocyclic ringand a substituted condensed aromatic heterocyclic ring, said cyclicportion comprising from 4 to 6 total atoms, from three to five carbonatoms and from one to three hetero-atoms, said hetero-atoms in additionto N being independently selected from the group consisting of N, O andS, said substituents of the substi tuted heterocyclic ring andsubstituted condensed aromatic heterocyclic ring being selected from thegroup consisting of a mono-valent hydrocarbon radical, a non-hydrocarbonsubstituted mono-valent hydrocarbon radical, OH and NH said total ringstructure comprising from three to about 100 carbon atoms; saidoilmiscible compound being present in an amount sufficient to improvethe wear properties of the lubricating composition toward silver.

2. The composition of claim 1, wherein the total number of carbon atomscontained in I is between about two and about 30, when R, and R incombination with N form a ring structure, said total ring structurecomprises from about four to about 30 carbon atoms; when R and R incombination with N form a ring structure, said total ring structurecomprises from about five to about 25 carbon atoms; and the N and OH areseparated by from one to four carbon atoms.

3. The composition of claim 1 wherein R and R are independently selectedfrom the group consisting of H and R-OH where R is an alkyl radicalhaving from one to four carbon atoms, said cyclic portions of said ringstructures containing N comprise from five to six total atoms, saidhetero-atoms being N; said oil-miscible compound being present in anamount of at least about 0.01 percent by weight of the totalcomposition.

4. The composition of claim 1 wherein said oilmiscible compound isselected from the group consisting of 8-hydroxyquinoline; disalicylalpropylene diimine; l-hydroxyethyl, 2-alkenyl imidazoline; lhydroxyethyl,2-alkyl imidazoline and mixtures thereof, wherein the alkenyl and alkylgroups contain between about seven and about 29 carbon atoms.

5. The composition of claim 1 wherein said oilmiscible compound ispresent in an amount of at least about 0.01 percent by weight of thetotal composition.

6. The composition of claim 2 wherein said oilmiscible compound ispresent in an amount of at least about 0.01 percent by weight of thetotal composition.

7. The composition of claim 4 wherein said oil miscible compound ispresent in an amount of at least about 0.01 percent by weight of thetotal composition.

8. The composition of claim 7 wherein said oilmiscible compound ispresent in an amount from about 0.01 percent to about 2.0 percent byweight of the total composition.

9. The composition of claim 1 wherein said carbonate overbased salt ispresent in an amount from about 0.1 percent to about 8 percent by weightof the total composition.

10. The composition of claim 6 wherein said carbonate overbased salt ispresent in an amount from about 0.1 percent to about 8 percent of thetotal composition.

ll. The composition of claim 8 wherein said carbonate overbased salt ispresent in an amount from about 0.1 percent to about 8 percent of thetotal composition.

12. The composition of claim 1 wherein said carbonate overbased salt isselected from the group consisting of calcium sulfonate, calcium phenateand mixtures thereof, and overbased as calcium carbonate.

13. The composition of claim 6 wherein said carbonate overbased salt isselected from the group consisting of calcium sulfonate, calcium phenateand mixtures thereof, and overbased as calcium carbonate.

14. The composition of claim 11 wherein said carbonate overbased salt isselected from the group consisting of calcium sulfonate, calcium phenateand mixtures thereof, and overbased as calcium carbonate.

15. The composition of claim 1 wherein said composition contains fromabout 1 percent to about 6 percent by weight of at least one ashlessdetergent, said ashless detergent being a compound which comprises ahydrocarbon portion of sufficient size to render said compound oilsoluble and at least one non-metallic polar portion which provides asubstantial portion of the detergent action.

16. The composition of claim wherein said composition contains fromabout 1 percent to about 6 percent by weight of at least one ashlessdetergent, said ashless detergent being a compound which comprises ahydrocarbon portion of sufficient size to render said compound oilsoluble and at least one non-metallic polar portion which provides asubstantial portion of the detergent action.

17. The composition of claim 6 wherein said composition contains fromabout 1 percent to about 6 percent by weight of at least one ashlessdetergent, said ashless detergent being a compound which comprises ahydrocarbon portion of sufficient size to render said compound oilsoluble and at least one non-metallic polar portion which provides asubstantial portion of the detergent action.

18. The composition of claim 7 wherein said composition contains fromabout 1 percent to about 6 percent by weight of at least one ashlessdetergent, said ashless detergent being a compound which comprises ahydrocarbon portion of sufficient size to render said compound oilsoluble and at least one non-metallic polar portion which provides asubstantial portion of the detergent action.

19. The composition of claim 18, wherein said carbonate overbased saltis selected from the group consisting of calcium sulfonate, calciumphenate and mixtures thereof and overbased as calcium carbonate, saidcarbonate overbased salt being present in an amount from about 0.1percent to about 8 percent by weight of the total composition, saidcomposition containing from about 1 percent to about 6 percent by weightof at least one ashless detergent, said ashless detergent being acompound which comprises a hydrocarbon portion of sufficient size torender said compound oil soluble and at least one non-metallic polarportion which provides a substantial portion of the detergent action.

20. The composition of claim 19 wherein said oilmiscible compound ispresent in an amount from about 0.01 percent to about 2.0 percent byweight of the total composition.

21. In a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of claim 1 on the components of said engine requiringlubrication.

22. In a method for lubricating an internal combustion engine, theimprovement which comprises main taining a lubricating amount of thecomposition of claim 2 on the components of said engine requiringlubrication.

23. In a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of claim 3 on the components of said engine requiringlubrication.

24. In a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of claim 4 on the components of said engine requiringlubrication.

25. In a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of claim 5 on the components of said engine requiringlubrication.

26. The method of claim 25 wherein said engine comprises silvercomponents requiring lubrication.

27. in a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of claim 10 on the components of said engine requiringlubrication.

28. The method of claim 27 wherein said engine is a railroad dieselengine and comprises silver components requiring lubrication.

29. In a method for lubricating an internal combustion engine, theimprovement which comprises maintaining a lubricating amount of thecomposition of ing lubrication, the improvement which comprisesmaintaining a lubricating amount of the composition of claim 20 on thecomponents of said engine requiring lubrication.

32. The method of claim 31 wherein said engine is a railroad dieselengine.

2. The composition of claim 1, wherein the total number of carbon atomscontained in I is between about two and about 30, when R1 and R2 incombination with N form a ring structure, said total ring structurecomprises from about four to about 30 carbon atoms; when R and R1 incombination with N form a ring structure, said total ring structurecomprises from about five to about 25 carbon atoms; and the N and OH areseparated by from one to four carbon atoms.
 3. The composition of claim1 wherein R1 and R2 are independently selected from the group consistingof H and R-OH where R is an alkyl radical having from one to four carbonatoms, said cyclic portions of said ring structures containing Ncomprise from five to six total atoms, said hetero-atoms being N; saidoil-miscible compound being present in an amount of at least about 0.01percent by weight of the total composition.
 4. The composition of claim1 wherein said oil-miscible compound is selected from the groupconsisting of 8-hydroxyquinoline; disalicylal propylene diimine;1-hydroxyethyl, 2-alkenyl imidazoline; 1-hydroxyethyl, 2-alkylimidazoline and mixtures thereof, wherein the alkenyl and alkyl groupscontain between about seven and about 29 carbon atoms.
 5. Thecomposition of claim 1 wherein said oil-miscible compound is present inan amount of at least about 0.01 percent by weight of the totalcomposition.
 6. The composition of claim 2 wherein said oil-misciblecompound is present in an amount of at least about 0.01 percent byweight of the total composition.
 7. The composition of claim 4 whereinsaid oil-miscible compound is present in an amount of at least about0.01 percent by weight of the total composition.
 8. The composition ofclaim 7 wherein said oil-miscible compound is present in an amount fromabout 0.01 percent to about 2.0 percent by weight of the totalcomposition.
 9. The composition of claim 1 wherein said carbonateoverbased salt is present in an amount from about 0.1 percent to about 8percent by weight of the total composition.
 10. The composition of claim6 wherein said carbonate overbased salt is present in an amount fromabout 0.1 percent to about 8 percent of the total composition.
 11. Thecomposition of claim 8 wherein said carbonate overbased salt is presentin an amount from about 0.1 percent to about 8 percent of the totalcomposition.
 12. The composition of claim 1 wherein said carbonateoverbased salt is selected from the group consisting of calciumsulfonate, calcium phenate and mixtures thereof, and overbased ascalcium carbonate.
 13. The composition of claim 6 wherein said carbonateoverbased salt is selected from the group consisting of calciumsulfonate, calcium phenate and mixtures thereof, and overbased ascalcium carbonate.
 14. The composition of claim 11 wherein saidcarbonate overbased salt is selected from the group consisting ofcalcium sulfonate, calcium phenate and mixtures thereof, and overbasedas calcium carbonate.
 15. The composition of claim 1 wherein saidcomposition contains from about 1 percent to about 6 percent by weightof at least one ashless detergent, said ashless detergent being acompound which comprises a hydrocarbon portion of sufficient size torender said compound oil soluble and at least one non-metallic polarportion which provides a substantial portion of the detergent action.16. The composition of claim 5 wherein said composition contains fromabout 1 percent to about 6 percent by weight of at least one ashlessdetergent, said ashless detergent being a compound which comprises ahydrocarbon portion of sufficient size to render said compound oilsoluble and at least one non-metallic polar portion which provides asubstantial portion of the detergent action.
 17. The composition ofclaim 6 wherein said composition contains from about 1 percent to about6 percent by weight of at least one ashless detergent, said ashlessdetergent being a compound which comprises a hydrocarbon portion ofsufficient siZe to render said compound oil soluble and at least onenon-metallic polar portion which provides a substantial portion of thedetergent action.
 18. The composition of claim 7 wherein saidcomposition contains from about 1 percent to about 6 percent by weightof at least one ashless detergent, said ashless detergent being acompound which comprises a hydrocarbon portion of sufficient size torender said compound oil soluble and at least one non-metallic polarportion which provides a substantial portion of the detergent action.19. The composition of claim 18, wherein said carbonate overbased saltis selected from the group consisting of calcium sulfonate, calciumphenate and mixtures thereof and overbased as calcium carbonate, saidcarbonate overbased salt being present in an amount from about 0.1percent to about 8 percent by weight of the total composition, saidcomposition containing from about 1 percent to about 6 percent by weightof at least one ashless detergent, said ashless detergent being acompound which comprises a hydrocarbon portion of sufficient size torender said compound oil soluble and at least one non-metallic polarportion which provides a substantial portion of the detergent action.20. The composition of claim 19 wherein said oil-miscible compound ispresent in an amount from about 0.01 percent to about 2.0 percent byweight of the total composition.
 21. In a method for lubricating aninternal combustion engine, the improvement which comprises maintaininga lubricating amount of the composition of claim 1 on the components ofsaid engine requiring lubrication.
 22. In a method for lubricating aninternal combustion engine, the improvement which comprises maintaininga lubricating amount of the composition of claim 2 on the components ofsaid engine requiring lubrication.
 23. In a method for lubricating aninternal combustion engine, the improvement which comprises maintaininga lubricating amount of the composition of claim 3 on the components ofsaid engine requiring lubrication.
 24. In a method for lubricating aninternal combustion engine, the improvement which comprises maintaininga lubricating amount of the composition of claim 4 on the components ofsaid engine requiring lubrication.
 25. In a method for lubricating aninternal combustion engine, the improvement which comprises maintaininga lubricating amount of the composition of claim 5 on the components ofsaid engine requiring lubrication.
 26. The method of claim 25 whereinsaid engine comprises silver components requiring lubrication.
 27. In amethod for lubricating an internal combustion engine, the improvementwhich comprises maintaining a lubricating amount of the composition ofclaim 10 on the components of said engine requiring lubrication.
 28. Themethod of claim 27 wherein said engine is a railroad diesel engine andcomprises silver components requiring lubrication.
 29. In a method forlubricating an internal combustion engine, the improvement whichcomprises maintaining a lubricating amount of the composition of claim19 on the components of said engine requiring lubrication.
 30. Themethod of claim 29 wherein said engine is a railroad diesel engine andcomprises silver components requiring lubrication.
 31. In a method forlubricating an internal combustion engine which comprises silvercomponents requiring lubrication, the improvement which comprisesmaintaining a lubricating amount of the composition of claim 20 on thecomponents of said engine requiring lubrication.
 32. The method of claim31 wherein said engine is a railroad diesel engine.